Defender counting out loud during inbound

[twing1115]

I'm a coach and would like to get some clarification. When an offensive team is inbounding the ball I instruct my player who is defending the inbounder to count out loud to five. Yesterday I was told that my players were not allowed to do this. The ref said that I could say anything else "Apples,Apples Apples" but not numbers. I have been searching high and low in a rule book for a rule preventing a team from doing this. The ref gave a warning and said that we could be called for unsportsmanlike or disconsertion. I've read about disconcertion and have only seen explanations that relate to free throws. Please help me out.